使用 fork 后，可能需要获取 fork 的进程的运行状况，比如有没有异常、崩溃。wait 在 man 中关键的描述如下：All of these system calls are used to wait for state changes in a child of the calling process, and obtain information about the child whose state has changed. A state change is considered to be: the child terminated; the child was stopped by a signal; or the child was resumed by a signal.

jsoncpp

soncpp is an implementation of a JSON (http://json.org ) reader and writer in C++. JSON (JavaScript Object Notation) is a lightweight data-interchange format. It is easy for humans to read and write. It is easy for machines to parse and generate.

报错：configure: error: Your operating system’s lex is insufficient to compile libpcap. flex is a lex replacement that has many advantages, including being able to compile libpcap. For more information, seehttp://www.gnu.org/software/flex/flex.html .